Traffic protection apparatus



Feb. 5, 1952 F. T. FEREDAY, SR

TRAFFIC PROTECTION APPARATUS 2 SHEETS--SHEET l Filed Feb. 20, 1947 v I i517 Truck @'b-z vae 27? am, M R @0m [.6 171 m m Z /M ww p b l 1L@ 1 HIS WOIZNEY' Feb. 5, 1952 Filed Feb. 20, 1947 TRAFFIC PROTECTION APPARATUS F. T. FEREDAY, SR 2,584,566

2 SHEETS-SHEET 2 Patented Feb. 5, 1952 TRAFFIC- PROTECTION APPARATUS Frederick T.,Fereday, Sr., Louisville, Ky., assigner to Westinghouse Air Brake Company, a

y ration of Pennsylvania ApplicationFehruary 20, 1947, Serial No. 729,683

1i claims. (c1. 24a-219) My invention relates to traino protection apparatus, and particularly to apparatus for providing crossover protection for trains moving along railway tracks which are interconnected by a crossover track through hand-operated track switches.

A requisite for crossover protection apparatus is that it must be so arranged that a, car or locomotive, while occupying a crossover such, for example, as one connecting two main tracks, while the switches are in the normal position for train movements along the main tracks, will cause a signal for each main track to indicate stop if the car or locomotive is within fouling distance of that main track. In crossover protection schemes embodying track circuits, one character istic should thereforebe high shunting sensitivity in order to insure that the crossover track circuits will be shunted when voccupied by a car or train, although the crossover track has high contact resistance due to the infrequency of train movements over the crossover.

One feature of my invention is the provision of improved shunting sensitivity through determination of the condition of occupancy of a crossover track by the picking up of a track relay instead of by release of a track relay.

Another feature of my invention is the provision of one track circuit including the rails f two sections of a crossover track.

Stillanother feature of my invention is an arrangement embodying a relay which has two windings, one of which performs the functions of a track relay and the other of which performs the functions of a stick relay.

The apparatus of my invention is an improvement over that which is disclosed in the copending application, Serial No. 671,191, lecl May 21, 1946, by Lowell B. Yarbrough for traffic protection apparatus.

I shall describe three forms of apparatus. ernbodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic view showing one form'of apparatus embodying my invention, in which a crossover track is divided into two sections and one track circuit is arranged to include the rails of both sections for controlling one slow release track relay through back contacts of any associated stick relay; Fig. 2 is a diagrammatic view showing a modiied'form of the apparatus of Fig'. 1, in which one relay having two windings is. used and one of the windings performs the functions of the track relay shown in Fig. 1 and controlsv a corpofront contact. which closes before a back contact' of the relay opens, and the other winding performs. the functions .of thev stick relay shownin Fig. 1; and Fig. 3 is a diagrammatic View, similar to Fig.. 2, showing a further modied form of the apparatus of Fig. 1, in which a relay having two windings isr provided with continuity contacts each of which becomes closedl at its front point before it opens at its back point Vwhen this relay becomes energized.

Similar reference characters refer to similar parts in each of the views. y

ReferringY firstto Fig. l, a stretch of railway is shown comprising two main tracks designated by the reference characters IT andZT, connected with each other by a crossover track through hand-operated switches, designated byfthe reference characters IW and2W... The crossover track is divided by insulated joints 2 into two sections IX and 2X. Y .k

VA contact device 3 is operated in conjunction with each of the switchesIW` and 2W. Each of these contacts is arranged to ybe closed whenjits switch is in the normal position, as shown in the drawing, for traffic movements along the as so-i ciated main track, and to be open when Aits switch is in the reverse position for traffic movements over the crossover track. Y

One track circuit is provided, including the rails of both sections IX and 2X of the crossover track. Sections IX and 2X are interconnected, at their adjacent ends, through back contactsfof a Istick relay SR. A slow release track relay 3R is connected through a usual impedance 5 across the rails of section 2X adjacent theopposite end of this section. A suitable source of current, shown as a, battery Q, is at times connected across the rails of section IX, adjacent the opposite end of this section, through switch contacts 3 and through back contacts of relay SR.

Relay SR has a picky-up and a stick circuit` each controlledby the switch contacts, and the pick-up circuitr is also controlled by afront contact of relay 3R. v l

Signal control circuits for tracks IT and 2T include front contacts of relay SR, so that signals for these tracks can be cleared only if relay SR is energized, and will indicate stop if relay SR is deenergized. y

Referring next to Fig. 2, a stretch of railway is here also shown comprising two main tracks designated by the reference characters IT and 2T, connected with each other by a crossover track through` hand-operated switches IW and The crossover track is here also divided by 3 insulated joints 2 into two sections IX and 2X.

Switch contacts 3 are operated in conjunction with switches IW and 2W, as in Fig. 1.

One track circuit is provided, including the rails of both sections IX and 2X of the crossover, as in Fig. l. Sections IX and 2X are here interconnected ,at their adjacent y. end-sl through a jumper 4 and a back contact of a track and stick relay R, instead of through two back contacts of a relay SR as shown in Fig. 1. y

Relay R has a rst winding Ir connected end of section 2X; A battery Q is at times connected across the opposite end of section IX through switch contacts 3 and through back contacts of relay R.

restores switches IW and 2W to their normal position, but that a car is left standing on section IX.

Upon restoration of switches IW and 2W to the normal position, a track circuit is completed, passing from battery Q, through contacts 3 of switches, |W,and.,2W. bakpointof. Contact G 0f relay SR,f-fanfimpedance' l-II, rail .Ia of section IX, back Vpoint o'contact II` of relay SR, rail Ib of section 2X, winding of relay 3R, impedance 5,rail la of section 2X, contact I2 of relay SR, through a usual impedance 5 across the opposite rail Ib-of'section IX, and back'point of contact I3 of relayySR, backv to battery Q. Relay 3R,

" however, von' accountof being shunted by the car Relay R has also a second winding 21' which`- is controlled by switch contacts 3 and by a front contact of relay R. This front contact of relay R is adjusted to becomel closed before the back contactsv of relay R open when that relay becomes energized.

Signal control circuits for tracks IT and 2T include front contacts of relay R.

Referring now to Fig. 3, the arrangement shown here differs from that shown in Fig. 2 in that relay R is here equipped with three contacts of the type known as continuity contacts, each of which becomes closed at its front point before it opens at its back point when relay R becomes energized. The front points of two of these contacts .are used in the control circuit for winding 2r of relay R, and the back points of the same two contacts are used for connecting battery Q across the rails of section IX. The third continuity contact is used for interconnecting one side of the adjacent ends of sections IX and 2X.

Having described, in general, the arrangement of the various parts of apparatus embodying my invention, I shall now describe the circuits and operation in detail.

As shown in the drawings, all parts of the various forms of apparatus are in the normal condition, that is, each of the switches IW and 217i7 is in the normal position for a train movement along main track IT or 2T, respectively; relay SR in Fig. 1, and winding 2r of relay Rin Figs. 2 and 3 are energized; relay 3R in Fig. l and winding Ir of relay R in Figs. 2 and 3 are deenergized; and the contacts of relays SR and R in the signal control circuits are closed.

In Fig. l, relay SR is energized by a stick circuit, this circuit passing from battery Q, through contacts 3 of switches IW and 2W, front point of contact.6 of relay SR, and winding of relay SR back to battery Q. With relay SR energized, contacts 8 and 9 of this relay are closed in signal control circuits for tracks IT and 2T, respectively. Also, with relay SR energized, a shunt path is connected across the rails of section IX through the front point of contact I3 of relay SR, and a shunt path is connected across the rails of sec'- tion 2X through the front point of contact I Ij of relay SR.

I shall assume that, with apparatus arranged as shown in Fig. l, a trainman reverses switches IW and 2W for a train to move over the cross# over track. Switch contacts 3 will therefore be opened, causing relay SR to become deenergized and in turn open the signal control circuits for tracks IT and 2T, whereupon the signals for these tracks will indicate stop.

I shall assume further that a train then moves over the crossover track from one of the main tracks to the other, and that a trainman then on sectionv IX, does not become energized. Relay SR, therefore, remains deenergized and the signals for'tracks-iTfand 2T remain at stop.

I shallalso assume further that the trainman then again reverses switches IW and 2W to permitremoval of the car from section IX, and, that after the car has been thusremoved, he again restores the switches to the normalrposition. Relay 3R will'thereupon become energized by the track circuit previously traced.

With relay 3R energized, a pick-up circuit is completed for relay SR, which is the same as the stick circuit previouslytraced for this relay except that it includescontact I of relay 3R instead of the front point'of contact 6 of relay SR. Re-

lay SR, upfonv becoming energized', lcompletes its stick circuit previously traced,` and closes its contacts 8 and 9 in the signal control circuits for tracks IT-and 2T.Y Y' Y In Fig. 2, the circuit by which Winding 2r of relay R is energized passes from battery Q, through contacts 3'of switches vIWV and 2W, contact I4 of relay R,"and winding 21' back to battery Q. With relay R energized, a shunt path is connected across the rails of section'IX through the front point of contact Il.

I shall assume that with apparatus as shown in Fig. 2, a trainman reverses switches IW and 2W for a train to move over the crossover track; Switch contacts 3 will thereby be opened, causing winding 2r of relay R to become deenergized. Front contacts I8 and *I9 of relay Rin the signal control circuits will therefore become opened. causing the signals for'tracks IT and 2T to vindicate stop.

` I shall assume further that a train then moves over the crossover track, and that a trainman then restores switches IW and 2W to the normal position, but that a car is left standing on section Upon the restoration of switches IW and 2W to the normal position, a track circuit is completed, passing from battery Q, through contacts 3 of switches IW and 2W, impedance I0, contact I5 of relay R, rail Ia of section IX, contact I6 of relay R, rail Ib of section 2X, winding Ir of relay R, impedance 5, rail I a of section 2X, jumper 4, rail Ib of section lIX',and the' back point of contact I'I of-relay R, back to battery Q. Winding Ir, on account of being lsl'iunted by the car in section IX,.remains deenergized, 'and the back contacts of relay R'therefore remain closed-and its front contacts remain open, so that the signals for tracks IT and 2T controlled by'this' relay will continue to indicate stop. Y

I shallv also assume further that the trainman again reversess'witchesIW and 2W, for removal of the ca`r from section IX, and that, after the car has been removed, he again restores switches IW and 2W to the normal position.

'i Windingv Ir will thereupon become energized' by the track circuit previouslytracedl for this relay. Winding Ir, upon becoming energized, closes contact III- of relay R, thereby completing a circuit previously traced for energizing winding 2r of relay R. The back contacts of relay R in the track circuit previously traced will now be opened, causing winding Ir to become deenergized.- The front contacts of relay R will, however, be held closed by winding 2r. Contacts I8 and I9 of this relay will therefore now be closed in signal control circuits for tracks IT and 2T.

Y kIn Fig. 3, the circuit by which winding 2r of relayv R is energized passes from battery Q, through contacts 3 of switches IW and 2W, front point of contact 20 of relay R, winding 2r, and front point of contact 2l of relay R, back to battery Q. With Winding 2r of relay R energized, a shunt path is completed across the rails of section I-X by contactV 23 of relay R..

I shall now assume that, with apparatus arranged as shown in Fig. 3, a trainman reverses switches IW and 2W' for a train to move over the crossover track. Switch contacts 3 will therefore open thecircuit traced for winding 2r of relay R, causing relay R to become deenergized. With relay R deenergized, contacts I8 and I9 of this relay will open the signal control circuits for tracks IT and 2T, causing the signals controlled by these circuits to indicate stop.

I shall assume further that a train proceeds over the crossover, and that the trainman restores. switches IW and 2W to the normal position, but that a car has been left on section I X.

With switches IW and 2W restored to the normal position, a track circuit is completed, passing from battery Q, through contacts 3 of switches IW and 2W, back point of contact 20 of relay R, impedance I0, rail Ia of section IX, contact 22 of relay R, rail Ib of section 2X, winding Ir, irrin pedance 5, rail Ia of section 2X, jumper 4, rail Ib of section IX, and the back point of contact 2| of relay R, back to battery Q. Winding Ir, on.

account of being shunted by the car on section IX, will remain deenergized, and the back contacts of relay R will therefore remain closed, and the front contacts will remain open, so that the signals for tracks IT and 2T controlled by this relay will continue to indicate stop.

I shall also assumefurther that a trainman again reverses switches IW and 2W for removal of the car from section IX and that, after the car has been thus removed, he again restores switches IW and 2W to the normal position. Winding I r will thereupon become energized by its track circuit previously traced. Winding Ir, upon becoming energized, completes the circuit previously traced for winding 2r through the front points of contacts 20 and 2l. Contacts 20 and 2| will then open at their back points, causing winding Ir to become deenergized. With the front contacts of relay R now closed, contacts I8 and I9 of relay R will be closed in the signal control circuits for tracks IT and 2T. y

Although I have herein shown and described only a few forms of apparatus embodying my invention, it is understood that various changes and modications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In tra'c protection apparatus for a stretch of railway in which two main tracks are interconnected by a crossover track which is" divided intotwo sections by means including a pair of insulated joints between adjacent ends of said sections, the combination comprising, a slow release track relay connected across thev rails of one of said sections adjacent its opposite end, a stick relay, a track battery connected across the rails of the other section adjacent its op'- posite end through normally closed contacts of the crossover track switches 'and through back contacts of said stick relay, a circuit pathV including a back contact of said stick relay for connecting one rail of one of said sections with a rail of the other section adjacent said pair of insulated joints, a second circuit path including a second back contact of said stick relay forinterconnecting the other rails of said sections adjacent said pair of insulated joints, a pick-up and a stick circuit for said stick relay each controlled by normally closed contacts of said crossover track switches and said pick-up circuit also controlled by a front contact of said track relay, and signal control means controlled by said stick relay.

2. In trafc protection apparatus for a stretch of railway in which two main tracks are interconnected by a crossover track through two hand-operated track switches each of which has a normal position for traino movements along its main track and a reverse position for traic movements over said crossover track andV in which said crossover track is divided into two sections, the combination comprising, 'a slow release 'track relay, a stick relay, a track circuit including the rails or" said crossover track and the winding of said track relay as well as a suitable source of current and also including back contacts of said stick relay for interconnecting said track sections and including normally closed contacts of said track switches, a pick-up and a stick circuit for said stick relay `each controlled by normally closed contacts of said switches and said pick-up circuitpalso controlled by a front contact of said track relay, and signal control means controlled by said stick relay.

3. In trafc protection apparatus for a stretch of railway in which two main tracks are interconnected by a crossover track through handoperated track switches and in which said crossover track is divided into two sections, the cornbination comprising, a stick relay, a contact of each of said switches each closed if its switch is in the Vposition for trafc movements along its main track but open if its switch is in the position for tranic movements over said crossover track, a slow release track relay connected across the rails of said crossover track adjacent one of its ends, a source of current connected across the rails of said crossover track adjacentl its other end through said switch contacts and through back contacts of said stick relay, means including a back contact of said stick relay for interconnecting said sections, a pick-up and a stick circuit for said stick relay each controlled by said switch contacts and said rpick-up circuit also controlled by a front contact of said track relay, and signal control means controlled by said stick relay.-

4. In trairlc protection apparatus for a `stretch of railway in which two main tracks are interconnected by a crossover track through handoperated track switches and in which said crossover track is divided into two sections, 'the combination comprising a contact of each of said switches each closed if its switch. is arranged fortraiiic movements along its main track but open `if its switch is arranged for traftic movements vover said crossover track, a stick relay, a track r'elay connected across the rails of one of said sections adjacent one end of said crossover track, a source of current connected across the rails of the other of said sections adjacent the opposite end of said crossover track through said switch contacts and through back contacts of said stick relay, means includingr back contacts of said stick relay for interconnecting said ltwo sections, a pick-up and a stick circuit for said stick relay each controlled by said switch contacts and said pick-up circuit also controlled by a front contact of said track relay, and signal control means controlled by said stick relay.

5. In traffic protection apparatus for a stretch of railway in which two main tracks are interconnected by a crossover track through handoperated track switches and in which said crossover track is divided into two sections, the combination comprising, a contact of each of said switches each closed if its switch is arranged for traic movements along its main track but open if its switch is arranged for traic movements over said crossover track, a stick relay winding, a track relay winding connected across the end of one of said sections adjacent one end of said crossover track, a source of current connected across the end of the other section adjacent the opposite end of said crossover track through said switch contacts and through back contacts controlled by said stick relay winding, means including a back contact controlled by said stick relay winding for interconnecting said track sections, a pick-up and a stick circuit for said stick relay winding each controlled by said switch contacts and said pick-up circuit also controlled by a front contact which is controlled by said track relay winding, and signal control means controlled by said stick relay winding.

6. In traiic protection apparatus for a stretch of railway in which two-main tracks are interconnected by a crossover track through handoperated track switches and in which said crossover track is divided into two sections, the combination comprising, a contact of each of said switches each closed if its switch is arranged for traffic movements along its main track but open if its switch is arranged for traflic movements over said crossover track, a stick relay Winding, a track relay Winding, means including a back contact controlled by said stick relay winding for interconnecting said track sections, a track circuit for said crossover track including said track relay winding and the rails of both of said sections interconnected by said means including a back contact controlled by said stick relay winding and also including a source of current controlled by said switch contacts, means controlled by said switch contacts and by said track relay winding for controlling said stick relay Winding, and signal control means' controlled by said stick relay winding.

7. In trafc protection apparatus for a stretch of railway in which two main tracks are interconnected by a crossover track through handoperated track switches and in which said crossover track is divided into two sections, the combination comprising, a contact of each of said switches each closed if its switch is arranged for traffic movements along its main track but open if its switch is arranged for trailic movements over said crossover track, a relay having a stick relay winding and a track relay Winding and having a 'front contact which closes before its back contacts open when said relay becomes energized, means including a backA contact controlled by said stick relay winding-for interconnecting said track sections, a track circuit for said crossover track including said track relay winding and the rails of both of said sections interconnected by said means including a back contact controlled by said stick relay winding and also including a source of current controlled by said switch contacts, means controlled by said switch contacts and by said front contact of said relay for controlling said stick relay winding, and signal control means controlled by said stick relay winding.

8. In traffic protection apparatus for a stretch of railway in which two main tracks are interconnected byY a crossover track through handoperated track switches and in which said crossover track is divided into two sections, the combination comprising, a contact of each of said switches each closed if its switch is arranged for trac movements along its main track but open if its switch is arranged for traiiic movements over said crossover track, a relay having a stick relay winding and a track relay winding yand having `continuity contacts each of which becomes closed at its front point before opening at its back point when said track relay Winding becomes energized, means including a back contact controlled by said stick relay winding for interconnecting said track sections, a track circuit for said crossover track including said track relay winding and the rails of both of said sections interconnected by said means including a back contact controlled by said stick relay winding and also including a source of current and the backpoints of two said continuity contacts and controlled by said switch contacts, a control circuit for said stick relay Winding including the front points of said two continuity contacts and controlled by saidswitch contacts, and signal control means controlled by said stick relay windlng.

9. In traflic protection apparatus for a stretch of railway in Which two main tracks are interconnected by a crossover track through two track switches one at each end of said crossover track and in which said crossover track is divided into two sections, the combination comprising, a contact of each of said switches each closed if its switch is arranged for traffic movements Yalong its main track but open if its switch is arranged for traic movements over said crossover track, a relay having a stick relay winding and a track relay winding and having a front contact which closes before its back contacts open when said relay becomes energized, said track relay winding connected across the end of one of said sections adjacent one end of said crossover track, a source of current connected across the end of the other section adjacent the opposite end of said crossover track through means including said switch contacts and a back contact controlled by said stick relay winding, means including a back contact controlled by said stick relay winding for interconnecting said track sections, means controlled by said switch contacts and by said front contact of said relay for controlling said stick relay winding, and signal control means controlled by said stick relay winding.

10. In traffic protection apparatus for a stretch of railway in which two main tracks are interconnected by a crossover track `through handoperated track switches and in which said cross- 76 over track is divided into vtwo sections, the com- 9 Y bination comprising, a contact of each of said switches each closed if its switch is in position for traffic movements along its main track but open if its switch is in position for trafc movements over said crossover track, a relay having a stick relay Winding and a track relay winding and having a front contact which closes before its back contacts open when said relay becomes energized, said track relay winding connected across the end of one of said sections adjacent one end of said crossover track, a source of current connected across the end of the other section adjacent the opposite end of said crossover track through said switch contacts and through back contacts controlled by said stick relay winding, means including a back contact controlled by said stick relay winding for interconnecting said track sections, a pick-up and a stick circuit for said stick relay winding each controlled by saidswitch contacts and said pick-up circuit also controlled by said front contact, and signal control means controlled by said stick relay winding.

11. In traffic protection apparatus for a stretch of railway in which two main tracks are interconnected by a crossover track through two track switches one at each end of said crossover track and in which said crossover track is divided into two sections, the combination comprising, a contact of each of said switches each closed if the associated switch is arranged for trafc movements along the associated main track but open 10 if said associated switch is arranged for traflic movements over said crossover track, a stick relay winding, a track relay winding connected across the end of one of said sections adjacent one end of said crossover track, a source of current connected across the end of the other section adjacent the opposite end of said crossover track through means including said switch contacts and a back contact controlled by said stick relay winding, means including a back Contact controlled by said `stick relay winding for interconnecting said track sections, means controlled by said Vswitch contacts and by said track relay winding for controlling said stick relay winding, and signal control means controlled by said stick relay winding.

FREDERICK T. FEREDAY, Sn.

REFERENCES CITED The following references are o1 record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,045,924 Reichard June 30, 1936 2,391,985 Langdon Jan. 1, 1946 2,442,735 Talbert June 1, 1948' FOREIGN PATENTS Number Country Date 617,873 France Feb. 26, 1927 

